August 2011 - Boost-users - lists.preview.boost.org

Cannot get Wave + Spirit Compile
by Alexander Feldman 29 Aug '11

29 Aug '11

Hi, I have (I suppose) a beginner problem -- cannot make wave + spirit compile. I think there is an iterator problem but I cannot understand the compiler error. I am attaching a small example and the error output - can somebody explain how to fix this? I have searched around a lot but can't find an answer to that. Thanks, -- Alex

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[math][tools][units] generic libraries not generic enough
by alfC 29 Aug '11

29 Aug '11

Hi, Lately I am using Boost.Units quite intensively for defining lots of thermodynamic functions. The other day I needed a root finding algorithm that can work on one of these functions. I look at couple of libraries,and I ended up rolling and adaptor that adimensionalizes the function on Boost.Units quantities, etc, etc. Then I though, hey! we have Boost.Math tools, even root finding algorithms, and these functions are *very* generic as Boost is supposed to be. And I found the function: boost::math::tools::bracket_and_solve_root which has the perfect underlying algorithm for the application. I started programming and after several compilation errors I realized that, as happened before, the functions are not generic enough. For example the arguments are bracket_and_solve_root( F f, const T& guess, const T& factor, bool rising, Tol tol, boost::uintmax_t& max_iter); in my case "guess" is an argument type of type boost::units::quantity<si::meter> but then "factor" has to be a *different* type. For this function to be generic one need that factor is of new type parameter. In my opinion the function should be template<typename F, typename T, typename Fact, typename Tol> bracket_and_solve_root( F f, const T& guess, const T& factor, bool rising, Tol tol, boost::uintmax_t& max_iter); to begin with (and then there is a chain of other internal changes). What do you think? should I open a bug ticket? Let's put it in more abstract way: T*T=T should not be a requirement for a root algorithm to work. Once and for all, can we give a name to the model type of which Boost.Units quantity models for? so the library writers stop assuming that T*T=T for numeric values and can improve half-way generic libraries? Other numeric libraries that suffer from this deficiency are Boost.Accumulators, Boost.Geometry, and Boost.Interval among the ones I tried. I think this issues should be addressed, not only to make them work with Boost.Units but also to bring those libraries to a higher level of generality. Just an opinion. Thank you, Alfredo

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Regarding boost.python build on windows 7 (64 bit) VC9.0
by Nori Vasudeva Pavan Kumar 29 Aug '11

29 Aug '11

Hi I am trying to develop some python applications which use boost.python extensions. I am very new to both VC and Boost. I am able to compile boost.python following the help i found out in google. But I am not able to build my dll library linking with boost libraries. I am not able to figure out what and all going wrong. If I make it static library to be generated, the code builds but my python script is not able to import the library. Could you please direct me to a link where I can find solutions to all the problems regarding building and developing applications using boost.python. Regards, Vasudev

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[chrono] using user + system process cpu time
by Julian Gonggrijp 28 Aug '11

28 Aug '11

Dear Chrono maintainers, Here's what I'd like to do: #include <boost/chrono.hpp> namespace bcr = boost::chrono; typedef bcr::process_cpu_clock clock; bcr::milliseconds foo ( ) { clock::time_point start = clock::now(); // run a test clock::time_point end = clock::now(); return (end.user() - start.user()) + (end.sys() - start.sys()); } However, it seems (from the manual) that bcr::process_cpu_clock doesn't provide an interface for retrieving the individual user and system components (except by passing it through a std::stringstream, but that's cumbersome). The only alternative that I can think of is to use bcr::process_user_cpu_clock and bcr::process_system_cpu_clock separately, like this: typedef bcr::process_user_cpu_clock uclock; typedef bcr::process_system_cpu_clock sclock; bcr::milliseconds foo ( ) { uclock::time_point ustart = uclock::now(); sclock::time_point sstart = sclock::now(); // run a test uclock::time_point uend = uclock::now(); sclock::time_point send = sclock::now(); return (uend - ustart) + (send - sstart); } But the latter approach is less elegant and I'm afraid that the result might be less reliable. Could you please advice me on the best way to find both the user and system components of the process cpu time taken by a piece of code? Thanks in advance, -Julian

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[MSM] looking for a recursive get_state_name
by Jan Vogelgesang 28 Aug '11

28 Aug '11

Hello, i'am looking for a way to get the names(s) of the innermost active state(s) of a MSM with composite states, e.g. for debugging purposes. In my application i use state machines with orthogonal regions and submachines. Currently i use code based on the example given for fill_state_names, see http://www.boost.org/doc/libs/1_47_0/libs/msm/doc/HTML/re02.html#d0e5385 It works well for for orthogonal regions. For for submachines only the name of the active submachine is returned. Instead i want the name of the innermost active state in each submachine. I already found 'recursive_get_transition_table', this seems to be a first step. But i don't know how to get the state id's on the path to innermost active state. Unfortunately i don't know much about boost::mpl, thus i'am a bit lost at the moment. Any suggestions on how to get the state id's on the path to the innermost active state? Or on a different approach to get the name of the innermost active state? Best regards, Jan

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[Boost][Test] Compile error with BOOST_REQUIRE_THROW
by Martin Desharnais 28 Aug '11

28 Aug '11

Hi, I've just found that we have a compiler error when using the BOOST_REQUIRE_THROW macro in a if/else statement with implicit block. Let's have an example: BOOST_AUTO_TEST_CASE(foo) { if(true) BOOST_REQUIRE_THROW(throw std::exception(), std::exception); else BOOST_REQUIRE_THROW(throw std::exception(), std::exception); } Will fail with: file.cpp: In member function ‘void foo::test_method()’: file.cpp:184:2: error: ‘else’ without a previous ‘if’ To make it work, we need to put explicit block: BOOST_AUTO_TEST_CASE(foo) { if(true) { BOOST_REQUIRE_THROW(throw std::exception(), std::exception); } else { BOOST_REQUIRE_THROW(throw std::exception(), std::exception); } } Wouldn't it be possible to add this block in the macro so library users don't have to care about? PS: Sorry for my writing, I'm not a native English speaker. -- Martin Desharnais martin.desharnais(a)gmail.com

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Reg : Boost Error - any.hpp
by Vijay 28 Aug '11

28 Aug '11

Hi, We are using boost version 1.31.0 in our C++ code. Our OS is HP-UX 11.31 Itanium. We use aCC compiler. While compiling my code, I'm getting the below error. Can any one help me to fix this issue ? "/opt/app/q1app2c4/boost-1.31.0/boost/any.hpp", line 125: error #2070: incomplete type is not allowed ValueType held; ^ detected during: instantiation of class "boost::any::holder<ValueType> [with ValueType=Fcif]" at line 32 instantiation of "boost::any::any(const ValueType &) [with ValueType=Fcif]" at line 35 of "/opt/app/q1app2c4/src/share/incl/Fcif.h" Cheers, Vijay....(V2K) E-mail to : v2k.sweet(a)gmail.com Catch me @ 9962003328, 7871181610 Blackberry PIN : 259943F3 "Life is just one grand sweet song, so start the music."

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language c
by Giordano Bruno 28 Aug '11

28 Aug '11

Does anyone recommend use boost preprocessor in c language for ARM development? Giordano

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Debugging openssl server and asio
by Allan Nielsen 27 Aug '11

27 Aug '11

Hi I'm trying to hack cpp-netlib to implement a https server. I have used the ssl server example from boost 1.46.1 which is working okay, but when I (think) I do the same thing in cpp-net lib I got this segmentation fault: #0 0x00007ffff7bbda57 in SSL_accept () from /usr/lib64/libssl.so.1.0.0 #1 0x00000000004c1702 in boost::network::http::sync_connection<boost::network::http::tags::http_server, handler>::socket (this=0x4d58ca) at /home/awn/git/buildroot5/git/gmbinit/test/cpp-netlib-0.9.2/boost/network/protocol/http/server/sync_connection.hpp:50 #2 0x00000000004d4e67 in boost::detail::function::function_invoker1<int (*)(SSL*), int, SSL*>::invoke (function_ptr=..., a0=0x731820) at /usr/include/boost-1_46/boost/function/function_template.hpp:95 #3 0x00000000004d0fd6 in boost::function1<int, SSL*>::operator() (this=0x73b490, a0=0x731820) at /usr/include/boost-1_46/boost/function/function_template.hpp:1013 #4 0x00000000004cde2f in boost::asio::ssl::detail::openssl_operation<boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::stream_socket_service<boost::asio::ip::tcp> > >::start (this=0x73b490) at /usr/include/boost-1_46/boost/asio/ssl/detail/openssl_operation.hpp:149 #5 0x00000000004df1b3 in boost::_mfi::mf0<int, boost::asio::ssl::detail::openssl_operation<boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::stream_socket_service<boost::asio::ip::tcp> > > >::operator() ( this=0x7fffffffc500, p=0x73b490) at /usr/include/boost-1_46/boost/bind/mem_fn_template.hpp:49 #6 0x00000000004dd693 in boost::_bi::list1<boost::_bi::value<boost::asio::ssl::detail::openssl_operation<boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::stream_socket_service<boost::asio::ip::tcp> > >*> >::operator()<int, boost::_mfi::mf0<int, boost::asio::ssl::detail::openssl_operation<boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::stream_socket_service<boost::asio::ip::tcp> > > >, boost::_bi::list0> (this=0x7fffffffc510, f=..., a=...) at /usr/include/boost-1_46/boost/bind/bind.hpp:243 #7 0x00000000004db687 in boost::_bi::bind_t<int, boost::_mfi::mf0<int, boost::asio::ssl::detail::openssl_operation<boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::stream_socket_service<boost::asio::ip::tcp> > > >, boost::_bi::list1<boost::_bi::value<boost::asio::ssl::detail::openssl_operation<boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::stream_socket_service<boost::asio::ip::tcp> > >*> > >::operator() (this=0x7fffffffc500) at /usr/include/boost-1_46/boost/bind/bind_template.hpp:20 #8 0x00000000004d980e in boost::asio::asio_handler_invoke<boost::_bi::bind_t<int, boost::_mfi::mf0<int, boost::asio::ssl::detail::openssl_operation<boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::stream_socket_service<boost::asio::ip::tcp> > > >, boost::_bi::list1<boost::_bi::value<boost::asio::ssl::detail::openssl_operation<boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::stream_socket_service<boost::asio::ip::tcp> > >*> > > > ( function=...) at /usr/include/boost-1_46/boost/asio/handler_invoke_hook.hpp:64 #9 0x00000000004d7b22 in boost_asio_handler_invoke_helpers::invoke<boost::_bi::bind_t<int, boost::_mfi::mf0<int, boost::asio::ssl::detail::openssl_operation<boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::stream_socket_service<boost::asio::ip::tcp> > > >, boost::_bi::list1<boost::_bi::value<boost::asio::ssl::detail::openssl_operation<boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::stream_socket_service<boost::asio::ip::tcp> > >*> > >, boost::_bi::bind_t<int, boost::_mfi::mf0<int, boost::asio::ssl::detail::openssl_operation<boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::stream_socket_service<boost::asio::ip::tcp> > > >, boost::_bi::list1<boost::_bi::value<boost::asio::ssl::detail::openssl_operation<boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::stream_socket_service<boost::asio::ip::tcp> > >*> > > > (function=..., context=...) at /usr/include/boost-1_46/boost/asio/detail/handler_invoke_helpers.hpp:39 #10 0x00000000004d5990 in boost::asio::detail::completion_handler<boost::_bi::bind_t<int, boost::_mfi::mf0<int, boost::asio::ssl::detail::openssl_operation<boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::stream_socket_service<boost::asio::ip::tcp> > > >, boost::_bi::list1<boost::_bi::value<boost::asio::ssl::detail::openssl_operation<boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::stream_socket_service<boost::asio::ip::tcp> > >*> > > >::do_complete (owner=0x734c60, base=0x72fb80) at /usr/include/boost-1_46/boost/asio/detail/completion_handler.hpp:63 #11 0x00000000004ae40b in boost::asio::detail::task_io_service_operation::complete (this=0x72fb80, owner=...) at /usr/include/boost-1_46/boost/asio/detail/task_io_service_operation.hpp:35 #12 0x00000000004b3fb2 in boost::asio::detail::strand_service::do_complete (owner=0x734c60, base=0x7308e0) at /usr/include/boost-1_46/boost/asio/detail/impl/strand_service.ipp:98 #13 0x00000000004ae40b in boost::asio::detail::task_io_service_operation::complete (this=0x7308e0, owner=...) at /usr/include/boost-1_46/boost/asio/detail/task_io_service_operation.hpp:35 #14 0x00000000004b0449 in boost::asio::detail::task_io_service::do_one (this=0x734c60, lock=..., this_idle_thread=0x7fffffffc790) at /usr/include/boost-1_46/boost/asio/detail/impl/task_io_service.ipp:278 #15 0x00000000004aff97 in boost::asio::detail::task_io_service::run (this=0x734c60, ec=...) at /usr/include/boost-1_46/boost/asio/detail/impl/task_io_service.ipp:130 #16 0x00000000004b0841 in boost::asio::io_service::run (this=0x7fffffffc980) at /usr/include/boost-1_46/boost/asio/impl/io_service.ipp:57 #17 0x00000000004ac04b in main (arg=1, argv=0x7fffffffcb18) at /home/awn/git/buildroot5/git/gmbinit/test/serverTest.cxx:51 As the problem is in SSL_accept () i expect there is something wrong with my SSL context which I create like this: boost::asio::ssl::context context_(io_service, boost::asio::ssl::context::sslv23); context_.set_verify_mode(boost::asio::ssl::context::verify_none); context_.use_certificate_chain_file("/etc/ssl/gamblify/gamblify.cert"); context_.use_private_key_file("/etc/ssl/gamblify/gamblify.pem", boost::asio::ssl::context::pem); The context is created in my main function, and then passed around as a reference. The type of my socket is: boost::asio::ssl::stream<boost::asio::ip::tcp::socket> socket_; I create it like this: socket_(service_, context) Accept is using the lowest layer which I return like this boost::asio::ssl::stream<boost::asio::ip::tcp::socket>::lowest_layer_type& socket() { return socket_.lowest_layer(); } I call async_accept like this: new_connection.reset(new sync_connection<Tag,Handler>(service_, handler_, context_)); acceptor_.async_accept(new_connection->socket(), boost::bind(&sync_server_base<Tag,Handler>::handle_accept, this, boost::asio::placeholders::error)); The handler looks like this: void handle_accept(boost::system::error_code const & ec) { if (!ec) { new_connection->start(); new_connection.reset(new sync_connection<Tag,Handler>(service_, handler_, context_)); acceptor_.async_accept(new_connection->socket(), boost::bind(&sync_server_base<Tag,Handler>::handle_accept, this, boost::asio::placeholders::error)); } } Eventually the accept handler and it is running start which looks like this: void start() { std::cerr << "Running start" << std::endl; socket_.async_handshake(boost::asio::ssl::stream_base::server, boost::bind(&sync_connection<Tag,Handler>::handle_handshake, this, boost::asio::placeholders::error)); } Then at some point before I reach the handle_handshake I get an segmentation fault... Can any body see any problems with this, or just give some hints on how to debug this kind of bugs... -- Allan W. Nielsen

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[MSM] How to use is_flag_active inside on_entry ?
by Gábor Márton 27 Aug '11

27 Aug '11

Hi, I would like to use is_flag_active<SomeFlag>() function inside one of my state's on_entry template function: struct StBladeDown : public msm::front::state<> { template<class Event, class FSM> void on_entry(Event const& event, FSM& fsm) { if(fsm.is_flag_active<FlagMaster>()) { // ERROR // doSomeThing(); } } }; However I got the following compile error: StOk.hpp: In member function 'void mr::mrd::amfo::StOk_::StBladeDown::on_entry(const Event&, FSM&)': StOk.hpp:78: error: expected primary-expression before '>' token StOk.hpp:78: error: expected primary-expression before ')' token However outside of the state machine, I mean if I first declare a state machine, I can use the is_flag_active: StAMFODirector backEnd; backEnd.start(); processEvent(backEnd,EvBladeDown()); processEvent(backEnd,EvMaster()); if(backEnd.is_flag_active<FlagMaster>()){ // OK _LOG_DEBUG("Flag Master active"); } If I use the front_end's is_flag_ I get compiler error again (no such function in msm::back::state_machine). Any idea how to use is_flag_active together with on_entry? Or if it is not possible are there any alternatives? Thanks for any help, Gabor

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